In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping case, or box, to fill any voids and/or to cushion the item during the shipping process. Some conventional protective packaging materials are plastic foam peanuts and plastic bubble pack. While these conventional plastic materials seem to adequately perform as cushioning products, they are not without disadvantages. Perhaps the most serious drawback of plastic bubble wrap and/or plastic foam peanuts is their effect on our environment. Quite simply, these plastic packaging materials are not biodegradable and thus they cannot avoid further multiplying our planet's already critical waste disposal problems. The non-biodegradability of these packaging materials has become increasingly important in light of many industries adopting more progressive policies in terms of environmental responsibility.
This and other disadvantages of conventional plastic packaging materials have made paper protective packaging material a very popular alterative. Paper is biodegradable, recyclable and renewable, making it an environmentally responsible choice for conscientious industries.
While paper in sheet form could possibly be used as a protective packaging material, it is usually preferable to convert the sheets of paper into a pad-like dunnage product. This conversion may be accomplished by a cushioning conversion machine, such as that disclosed in U.S. application Ser. Nos. 07/840,306; 07/712,203 (now U.S. Pat. No. 5,123,889); and 07/592,572. (These applications are all assigned to the assignee of the present invention and their entire disclosures are hereby incorporated by reference.) Such a cushioning conversion machine converts sheet-like stock material, such as paper in multi-ply form, into cut sections of dunnage. The stock material preferably consists of three superimposed webs or layers of biodegradable, recyclable and reusable thirty-pound Kraft paper rolled onto a hollow cylindrical tube. A thirty-inch wide roll of this paper, which is approximately 450 feet long, will weigh about 35 pounds and will provide cushioning equal to approximately four fifteen cubic foot bags of plastic foam peanuts while at the same time requiring less than one-thirtieth the storage space.
The cushioning conversion machine disclosed in the above-identified applications includes a frame, and conversion assemblies which convert the stock material into a dunnage strip. A cutting assembly cuts the dunnage strip into sections of a desired length. The cushioning conversion machine further includes a post-cutting constraining assembly which is of particular interest in the present application. The post-cutting constraining assembly is located downstream of the cutting assembly and is positioned so that a cut section will be urged or pushed therethrough by the approaching dunnage strip. As the cut section passes through the post-cutting constraining assembly, it is constrained circumferentially to improve its cushioning quality.
The post-cutting constraining assembly has proven to be a very advantageous feature in a cushioning conversion machine. However, in order to be effective, the cross-sectional geometry of the post-cutting constraining assembly must closely approximate that of a cut section. Moreover, as was explained above, it is the urging of the approaching dunnage strip which pushes the cut section through the post-cutting constraining assembly. Consequently, it is important for the cut section to be aligned both with the outlet of the downstream end plate and the inlet of the post-cutting constraining assembly. In other words, the cut section must have a smooth transition into the post-cutting constraining assembly.
In the above-identified applications, the cutting assembly includes a moving blade unit which travels between a rest position and a cutting position. More specifically, the blade will travel through one cycle of making a cutting stroke and a return stroke to the rest position. During the cutting stroke, the moving blade unit travels across the dunnage outlet opening and cuts the dunnage strip into a cut section, or pad, of a desired length.
Applicant believes that the cutting assemblies disclosed in the above-identified applications adequately perform their cutting functions. Nonetheless, applicant also appreciated that, in certain situations, alignment problems might be created due to the action of the moving blade unit. Specifically, the action of the moving blade unit during the cutting stroke sometimes tends to misalign the cut section relative to the outlet opening and/or the inlet to the post-cutting constraining assembly. As the moving blade unit returns to the rest position, the cut section will sometimes "rebound" back into alignment. However, the cut section sometimes remains at least partially misaligned even after the return stroke.
Accordingly, applicant developed the cutting/aligning assembly of the present invention to insure correct-alignment of the cut section relative to the outlet of the end plate and the inlet of the post-cutting constraining assembly. Specifically, the cutting/aligning assembly includes an automatic alignment device which automatically "re-aligns" the cut section with the outlet opening and the post-cutting constraining assembly during the return stroke of the moving blade unit. In other words, the alignment device insures a smooth transition for the cut section from the outlet opening through the post-cutting constraining assembly. In this manner, the cut section steadily continues its downstream travel as it is pushed by the approaching dunnage strip.
Applicant further appreciated the importance of accommodating a serious jam situation (i.e., when a pad somehow becomes positioned in such a manner that it causes substantial interference with the operation of the machine). Although serious jams are extremely rare with the preferred cushioning conversion machine, they often result in mechanical damage. Applicant also appreciated the importance of being able to conveniently correct a serious jam situation as this ability reduces machine downtime and operator aggravation. Accordingly, the cutting/aligning assembly of the present invention is specifically designed to substantially reduce the potential for damage during a serious jam situation and also to allow convenient correction of such a situation.
More particularly, the present invention provides a cushioning conversion machine for converting stock material into cut sections of dunnage. Conversion assemblies, which are mounted to the machine's frame, convert the stock material into a continuous dunnage strip. A cutting/aligning assembly is mounted on the machine's frame downstream of an outlet opening through which the dunnage strip emerges.
The cutting/aligning assembly includes a moving blade unit which is mounted on the frame in such a manner that it travels between a rest position and a cutting position whereat it cuts the dunnage strip into a cut section. The cutting/aligning assembly also includes an automatic alignment device which automatically aligns the cut section with the dunnage outlet opening when the blade unit is moved from the cutting position to the rest position. The automatic alignment device is unattached to the moving blade unit yet travels therewith during jam-free operation of the cushioning conversion machine. In the preferred embodiment, the alignment device includes a transition surface which is aligned with a side of the dunnage outlet opening when the blade unit is in the rest position and the alignment device is biased into a sliding, but unattached, contact arrangement with the blade unit. If the machine includes a post-cutting constraining assembly, the automatic alignment device will automatically align the cut section with the constraining assembly's inlet when the blade unit is moved from the cutting position to the rest position.
The biased, but unattached, arrangement between the alignment device and the blade unit protects the machine from damage during a serious jam situation. Specifically, if the alignment device was not unattached to the moving blade unit (i.e., if it was attached to the blade unit), the alignment device would be forced into following the moving blade unit. However, with the cutting/aligning assembly of the present invention, this forced following is eliminated whereby the potential for such damage is substantially reduced.
The biased, but unattached, arrangement between the alignment device and the blade unit also allows a serious jam situation to be easily rectified. Particularly, the alignment device may be pulled away from a jammed pad. The jammed pad may then be pushed back into proper alignment and operation of the machine may be resumed. Thus, with the cutting/aligning assembly of the present invention, a serious jam situation may be corrected in a matter of minutes thereby reducing machine downtime and operator aggravation.
The present invention provides these and other features hereinafter fully described and particularly pointed out in the claims. The following description and annexed drawings set forth in detail a certain illustrative embodiment of the invention. This embodiment is indicative, however, of but one of the various ways in which the principles of the invention may be employed.